In a case where signals are transmitted and received between two units, male and female connectors with electrodes corresponding to the number of signals have conventionally been used. Meanwhile, when one device is provided with a plurality of connectors, signal transmission is not accurately carried out when matching connectors are not connected to each other. Therefore, there is an incorrect fitting prevention connector in which key pins are provided at one or more portions of a terminal portion of one side connector, and holes, into which the key pins are inserted, are formed at the other side connector, so that the one side connector and the other side connector are not fitted to each other when the positions of the key pins do not correspond to the positions of the holes. In the incorrect fitting prevention connector as described above, since key pins are formed at empty pin positions of a connector, there is a limitation in the types of accurately fittable connectors. In addition, since the fitting is mechanical, key pins may be damaged when an incorrect connector is inserted.
In contrast, there is a connector which employs a fitting structure using an external shape of a connector without key pins. However, in this type of connector, since a difference in a physical shape is used, the combination of connectors is limited and only several different types may be coped with. Further, there is a problem in that a manufacturing cost is expensive because the shapes of the connectors are different from each other.
Therefore, Patent Document 1 discloses a connector in which magnets are provided in corresponding positions of a connector socket and a connector plug, and the corresponding magnets are attracted to each other only in matching connectors so as to connect the connectors to each other. Patent Document 2 discloses a connector in which connector pins themselves are formed of magnets, and connection is made only when polarities of magnets at seven positions are completely opposite to polarities of corresponding magnets.
[Patent Document 1] Japanese Laid-Open Patent Publication No. 2009-231114.
[Patent Document 2] Japanese Laid-Open Patent Publication No. 2004-247387.